/*
 * Copyright (c) 1997, 2006, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 *
 */

package java.awt.geom;

import java.io.Serializable;

/**
 * The <code>Rectangle2D</code> class describes a rectangle
 * defined by a location {@code (x,y)} and dimension
 * {@code (w x h)}.
 * <p>
 * This class is only the abstract superclass for all objects that
 * store a 2D rectangle.
 * The actual storage representation of the coordinates is left to
 * the subclass.
 *
 * @author Jim Graham
 * @since 1.2
 */
public abstract class Rectangle2D extends RectangularShape {

  /**
   * The bitmask that indicates that a point lies to the left of
   * this <code>Rectangle2D</code>.
   *
   * @since 1.2
   */
  public static final int OUT_LEFT = 1;

  /**
   * The bitmask that indicates that a point lies above
   * this <code>Rectangle2D</code>.
   *
   * @since 1.2
   */
  public static final int OUT_TOP = 2;

  /**
   * The bitmask that indicates that a point lies to the right of
   * this <code>Rectangle2D</code>.
   *
   * @since 1.2
   */
  public static final int OUT_RIGHT = 4;

  /**
   * The bitmask that indicates that a point lies below
   * this <code>Rectangle2D</code>.
   *
   * @since 1.2
   */
  public static final int OUT_BOTTOM = 8;

  /**
   * The <code>Float</code> class defines a rectangle specified in float
   * coordinates.
   *
   * @since 1.2
   */
  public static class Float extends Rectangle2D implements Serializable {

    /**
     * The X coordinate of this <code>Rectangle2D</code>.
     *
     * @serial
     * @since 1.2
     */
    public float x;

    /**
     * The Y coordinate of this <code>Rectangle2D</code>.
     *
     * @serial
     * @since 1.2
     */
    public float y;

    /**
     * The width of this <code>Rectangle2D</code>.
     *
     * @serial
     * @since 1.2
     */
    public float width;

    /**
     * The height of this <code>Rectangle2D</code>.
     *
     * @serial
     * @since 1.2
     */
    public float height;

    /**
     * Constructs a new <code>Rectangle2D</code>, initialized to
     * location (0.0,&nbsp;0.0) and size (0.0,&nbsp;0.0).
     *
     * @since 1.2
     */
    public Float() {
    }

    /**
     * Constructs and initializes a <code>Rectangle2D</code>
     * from the specified <code>float</code> coordinates.
     *
     * @param x the X coordinate of the upper-left corner of the newly constructed
     * <code>Rectangle2D</code>
     * @param y the Y coordinate of the upper-left corner of the newly constructed
     * <code>Rectangle2D</code>
     * @param w the width of the newly constructed <code>Rectangle2D</code>
     * @param h the height of the newly constructed <code>Rectangle2D</code>
     * @since 1.2
     */
    public Float(float x, float y, float w, float h) {
      setRect(x, y, w, h);
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public double getX() {
      return (double) x;
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public double getY() {
      return (double) y;
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public double getWidth() {
      return (double) width;
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public double getHeight() {
      return (double) height;
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public boolean isEmpty() {
      return (width <= 0.0f) || (height <= 0.0f);
    }

    /**
     * Sets the location and size of this <code>Rectangle2D</code>
     * to the specified <code>float</code> values.
     *
     * @param x the X coordinate of the upper-left corner of this <code>Rectangle2D</code>
     * @param y the Y coordinate of the upper-left corner of this <code>Rectangle2D</code>
     * @param w the width of this <code>Rectangle2D</code>
     * @param h the height of this <code>Rectangle2D</code>
     * @since 1.2
     */
    public void setRect(float x, float y, float w, float h) {
      this.x = x;
      this.y = y;
      this.width = w;
      this.height = h;
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public void setRect(double x, double y, double w, double h) {
      this.x = (float) x;
      this.y = (float) y;
      this.width = (float) w;
      this.height = (float) h;
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public void setRect(Rectangle2D r) {
      this.x = (float) r.getX();
      this.y = (float) r.getY();
      this.width = (float) r.getWidth();
      this.height = (float) r.getHeight();
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public int outcode(double x, double y) {
            /*
             * Note on casts to double below.  If the arithmetic of
             * x+w or y+h is done in float, then some bits may be
             * lost if the binary exponents of x/y and w/h are not
             * similar.  By converting to double before the addition
             * we force the addition to be carried out in double to
             * avoid rounding error in the comparison.
             *
             * See bug 4320890 for problems that this inaccuracy causes.
             */
      int out = 0;
      if (this.width <= 0) {
        out |= OUT_LEFT | OUT_RIGHT;
      } else if (x < this.x) {
        out |= OUT_LEFT;
      } else if (x > this.x + (double) this.width) {
        out |= OUT_RIGHT;
      }
      if (this.height <= 0) {
        out |= OUT_TOP | OUT_BOTTOM;
      } else if (y < this.y) {
        out |= OUT_TOP;
      } else if (y > this.y + (double) this.height) {
        out |= OUT_BOTTOM;
      }
      return out;
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public Rectangle2D getBounds2D() {
      return new Float(x, y, width, height);
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public Rectangle2D createIntersection(Rectangle2D r) {
      Rectangle2D dest;
      if (r instanceof Float) {
        dest = new Rectangle2D.Float();
      } else {
        dest = new Rectangle2D.Double();
      }
      Rectangle2D.intersect(this, r, dest);
      return dest;
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public Rectangle2D createUnion(Rectangle2D r) {
      Rectangle2D dest;
      if (r instanceof Float) {
        dest = new Rectangle2D.Float();
      } else {
        dest = new Rectangle2D.Double();
      }
      Rectangle2D.union(this, r, dest);
      return dest;
    }

    /**
     * Returns the <code>String</code> representation of this
     * <code>Rectangle2D</code>.
     *
     * @return a <code>String</code> representing this <code>Rectangle2D</code>.
     * @since 1.2
     */
    public String toString() {
      return getClass().getName()
          + "[x=" + x +
          ",y=" + y +
          ",w=" + width +
          ",h=" + height + "]";
    }

    /*
     * JDK 1.6 serialVersionUID
     */
    private static final long serialVersionUID = 3798716824173675777L;
  }

  /**
   * The <code>Double</code> class defines a rectangle specified in
   * double coordinates.
   *
   * @since 1.2
   */
  public static class Double extends Rectangle2D implements Serializable {

    /**
     * The X coordinate of this <code>Rectangle2D</code>.
     *
     * @serial
     * @since 1.2
     */
    public double x;

    /**
     * The Y coordinate of this <code>Rectangle2D</code>.
     *
     * @serial
     * @since 1.2
     */
    public double y;

    /**
     * The width of this <code>Rectangle2D</code>.
     *
     * @serial
     * @since 1.2
     */
    public double width;

    /**
     * The height of this <code>Rectangle2D</code>.
     *
     * @serial
     * @since 1.2
     */
    public double height;

    /**
     * Constructs a new <code>Rectangle2D</code>, initialized to
     * location (0,&nbsp;0) and size (0,&nbsp;0).
     *
     * @since 1.2
     */
    public Double() {
    }

    /**
     * Constructs and initializes a <code>Rectangle2D</code>
     * from the specified <code>double</code> coordinates.
     *
     * @param x the X coordinate of the upper-left corner of the newly constructed
     * <code>Rectangle2D</code>
     * @param y the Y coordinate of the upper-left corner of the newly constructed
     * <code>Rectangle2D</code>
     * @param w the width of the newly constructed <code>Rectangle2D</code>
     * @param h the height of the newly constructed <code>Rectangle2D</code>
     * @since 1.2
     */
    public Double(double x, double y, double w, double h) {
      setRect(x, y, w, h);
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public double getX() {
      return x;
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public double getY() {
      return y;
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public double getWidth() {
      return width;
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public double getHeight() {
      return height;
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public boolean isEmpty() {
      return (width <= 0.0) || (height <= 0.0);
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public void setRect(double x, double y, double w, double h) {
      this.x = x;
      this.y = y;
      this.width = w;
      this.height = h;
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public void setRect(Rectangle2D r) {
      this.x = r.getX();
      this.y = r.getY();
      this.width = r.getWidth();
      this.height = r.getHeight();
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public int outcode(double x, double y) {
      int out = 0;
      if (this.width <= 0) {
        out |= OUT_LEFT | OUT_RIGHT;
      } else if (x < this.x) {
        out |= OUT_LEFT;
      } else if (x > this.x + this.width) {
        out |= OUT_RIGHT;
      }
      if (this.height <= 0) {
        out |= OUT_TOP | OUT_BOTTOM;
      } else if (y < this.y) {
        out |= OUT_TOP;
      } else if (y > this.y + this.height) {
        out |= OUT_BOTTOM;
      }
      return out;
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public Rectangle2D getBounds2D() {
      return new Double(x, y, width, height);
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public Rectangle2D createIntersection(Rectangle2D r) {
      Rectangle2D dest = new Rectangle2D.Double();
      Rectangle2D.intersect(this, r, dest);
      return dest;
    }

    /**
     * {@inheritDoc}
     *
     * @since 1.2
     */
    public Rectangle2D createUnion(Rectangle2D r) {
      Rectangle2D dest = new Rectangle2D.Double();
      Rectangle2D.union(this, r, dest);
      return dest;
    }

    /**
     * Returns the <code>String</code> representation of this
     * <code>Rectangle2D</code>.
     *
     * @return a <code>String</code> representing this <code>Rectangle2D</code>.
     * @since 1.2
     */
    public String toString() {
      return getClass().getName()
          + "[x=" + x +
          ",y=" + y +
          ",w=" + width +
          ",h=" + height + "]";
    }

    /*
     * JDK 1.6 serialVersionUID
     */
    private static final long serialVersionUID = 7771313791441850493L;
  }

  /**
   * This is an abstract class that cannot be instantiated directly.
   * Type-specific implementation subclasses are available for
   * instantiation and provide a number of formats for storing
   * the information necessary to satisfy the various accessor
   * methods below.
   *
   * @see java.awt.geom.Rectangle2D.Float
   * @see java.awt.geom.Rectangle2D.Double
   * @see java.awt.Rectangle
   * @since 1.2
   */
  protected Rectangle2D() {
  }

  /**
   * Sets the location and size of this <code>Rectangle2D</code>
   * to the specified <code>double</code> values.
   *
   * @param x the X coordinate of the upper-left corner of this <code>Rectangle2D</code>
   * @param y the Y coordinate of the upper-left corner of this <code>Rectangle2D</code>
   * @param w the width of this <code>Rectangle2D</code>
   * @param h the height of this <code>Rectangle2D</code>
   * @since 1.2
   */
  public abstract void setRect(double x, double y, double w, double h);

  /**
   * Sets this <code>Rectangle2D</code> to be the same as the specified
   * <code>Rectangle2D</code>.
   *
   * @param r the specified <code>Rectangle2D</code>
   * @since 1.2
   */
  public void setRect(Rectangle2D r) {
    setRect(r.getX(), r.getY(), r.getWidth(), r.getHeight());
  }

  /**
   * Tests if the specified line segment intersects the interior of this
   * <code>Rectangle2D</code>.
   *
   * @param x1 the X coordinate of the start point of the specified line segment
   * @param y1 the Y coordinate of the start point of the specified line segment
   * @param x2 the X coordinate of the end point of the specified line segment
   * @param y2 the Y coordinate of the end point of the specified line segment
   * @return <code>true</code> if the specified line segment intersects the interior of this
   * <code>Rectangle2D</code>; <code>false</code> otherwise.
   * @since 1.2
   */
  public boolean intersectsLine(double x1, double y1, double x2, double y2) {
    int out1, out2;
    if ((out2 = outcode(x2, y2)) == 0) {
      return true;
    }
    while ((out1 = outcode(x1, y1)) != 0) {
      if ((out1 & out2) != 0) {
        return false;
      }
      if ((out1 & (OUT_LEFT | OUT_RIGHT)) != 0) {
        double x = getX();
        if ((out1 & OUT_RIGHT) != 0) {
          x += getWidth();
        }
        y1 = y1 + (x - x1) * (y2 - y1) / (x2 - x1);
        x1 = x;
      } else {
        double y = getY();
        if ((out1 & OUT_BOTTOM) != 0) {
          y += getHeight();
        }
        x1 = x1 + (y - y1) * (x2 - x1) / (y2 - y1);
        y1 = y;
      }
    }
    return true;
  }

  /**
   * Tests if the specified line segment intersects the interior of this
   * <code>Rectangle2D</code>.
   *
   * @param l the specified {@link Line2D} to test for intersection with the interior of this
   * <code>Rectangle2D</code>
   * @return <code>true</code> if the specified <code>Line2D</code> intersects the interior of this
   * <code>Rectangle2D</code>; <code>false</code> otherwise.
   * @since 1.2
   */
  public boolean intersectsLine(Line2D l) {
    return intersectsLine(l.getX1(), l.getY1(), l.getX2(), l.getY2());
  }

  /**
   * Determines where the specified coordinates lie with respect
   * to this <code>Rectangle2D</code>.
   * This method computes a binary OR of the appropriate mask values
   * indicating, for each side of this <code>Rectangle2D</code>,
   * whether or not the specified coordinates are on the same side
   * of the edge as the rest of this <code>Rectangle2D</code>.
   *
   * @param x the specified X coordinate
   * @param y the specified Y coordinate
   * @return the logical OR of all appropriate out codes.
   * @see #OUT_LEFT
   * @see #OUT_TOP
   * @see #OUT_RIGHT
   * @see #OUT_BOTTOM
   * @since 1.2
   */
  public abstract int outcode(double x, double y);

  /**
   * Determines where the specified {@link Point2D} lies with
   * respect to this <code>Rectangle2D</code>.
   * This method computes a binary OR of the appropriate mask values
   * indicating, for each side of this <code>Rectangle2D</code>,
   * whether or not the specified <code>Point2D</code> is on the same
   * side of the edge as the rest of this <code>Rectangle2D</code>.
   *
   * @param p the specified <code>Point2D</code>
   * @return the logical OR of all appropriate out codes.
   * @see #OUT_LEFT
   * @see #OUT_TOP
   * @see #OUT_RIGHT
   * @see #OUT_BOTTOM
   * @since 1.2
   */
  public int outcode(Point2D p) {
    return outcode(p.getX(), p.getY());
  }

  /**
   * Sets the location and size of the outer bounds of this
   * <code>Rectangle2D</code> to the specified rectangular values.
   *
   * @param x the X coordinate of the upper-left corner of this <code>Rectangle2D</code>
   * @param y the Y coordinate of the upper-left corner of this <code>Rectangle2D</code>
   * @param w the width of this <code>Rectangle2D</code>
   * @param h the height of this <code>Rectangle2D</code>
   * @since 1.2
   */
  public void setFrame(double x, double y, double w, double h) {
    setRect(x, y, w, h);
  }

  /**
   * {@inheritDoc}
   *
   * @since 1.2
   */
  public Rectangle2D getBounds2D() {
    return (Rectangle2D) clone();
  }

  /**
   * {@inheritDoc}
   *
   * @since 1.2
   */
  public boolean contains(double x, double y) {
    double x0 = getX();
    double y0 = getY();
    return (x >= x0 &&
        y >= y0 &&
        x < x0 + getWidth() &&
        y < y0 + getHeight());
  }

  /**
   * {@inheritDoc}
   *
   * @since 1.2
   */
  public boolean intersects(double x, double y, double w, double h) {
    if (isEmpty() || w <= 0 || h <= 0) {
      return false;
    }
    double x0 = getX();
    double y0 = getY();
    return (x + w > x0 &&
        y + h > y0 &&
        x < x0 + getWidth() &&
        y < y0 + getHeight());
  }

  /**
   * {@inheritDoc}
   *
   * @since 1.2
   */
  public boolean contains(double x, double y, double w, double h) {
    if (isEmpty() || w <= 0 || h <= 0) {
      return false;
    }
    double x0 = getX();
    double y0 = getY();
    return (x >= x0 &&
        y >= y0 &&
        (x + w) <= x0 + getWidth() &&
        (y + h) <= y0 + getHeight());
  }

  /**
   * Returns a new <code>Rectangle2D</code> object representing the
   * intersection of this <code>Rectangle2D</code> with the specified
   * <code>Rectangle2D</code>.
   *
   * @param r the <code>Rectangle2D</code> to be intersected with this <code>Rectangle2D</code>
   * @return the largest <code>Rectangle2D</code> contained in both the specified
   * <code>Rectangle2D</code> and in this <code>Rectangle2D</code>.
   * @since 1.2
   */
  public abstract Rectangle2D createIntersection(Rectangle2D r);

  /**
   * Intersects the pair of specified source <code>Rectangle2D</code>
   * objects and puts the result into the specified destination
   * <code>Rectangle2D</code> object.  One of the source rectangles
   * can also be the destination to avoid creating a third Rectangle2D
   * object, but in this case the original points of this source
   * rectangle will be overwritten by this method.
   *
   * @param src1 the first of a pair of <code>Rectangle2D</code> objects to be intersected with each
   * other
   * @param src2 the second of a pair of <code>Rectangle2D</code> objects to be intersected with
   * each other
   * @param dest the <code>Rectangle2D</code> that holds the results of the intersection of
   * <code>src1</code> and <code>src2</code>
   * @since 1.2
   */
  public static void intersect(Rectangle2D src1,
      Rectangle2D src2,
      Rectangle2D dest) {
    double x1 = Math.max(src1.getMinX(), src2.getMinX());
    double y1 = Math.max(src1.getMinY(), src2.getMinY());
    double x2 = Math.min(src1.getMaxX(), src2.getMaxX());
    double y2 = Math.min(src1.getMaxY(), src2.getMaxY());
    dest.setFrame(x1, y1, x2 - x1, y2 - y1);
  }

  /**
   * Returns a new <code>Rectangle2D</code> object representing the
   * union of this <code>Rectangle2D</code> with the specified
   * <code>Rectangle2D</code>.
   *
   * @param r the <code>Rectangle2D</code> to be combined with this <code>Rectangle2D</code>
   * @return the smallest <code>Rectangle2D</code> containing both the specified
   * <code>Rectangle2D</code> and this <code>Rectangle2D</code>.
   * @since 1.2
   */
  public abstract Rectangle2D createUnion(Rectangle2D r);

  /**
   * Unions the pair of source <code>Rectangle2D</code> objects
   * and puts the result into the specified destination
   * <code>Rectangle2D</code> object.  One of the source rectangles
   * can also be the destination to avoid creating a third Rectangle2D
   * object, but in this case the original points of this source
   * rectangle will be overwritten by this method.
   *
   * @param src1 the first of a pair of <code>Rectangle2D</code> objects to be combined with each
   * other
   * @param src2 the second of a pair of <code>Rectangle2D</code> objects to be combined with each
   * other
   * @param dest the <code>Rectangle2D</code> that holds the results of the union of
   * <code>src1</code> and <code>src2</code>
   * @since 1.2
   */
  public static void union(Rectangle2D src1,
      Rectangle2D src2,
      Rectangle2D dest) {
    double x1 = Math.min(src1.getMinX(), src2.getMinX());
    double y1 = Math.min(src1.getMinY(), src2.getMinY());
    double x2 = Math.max(src1.getMaxX(), src2.getMaxX());
    double y2 = Math.max(src1.getMaxY(), src2.getMaxY());
    dest.setFrameFromDiagonal(x1, y1, x2, y2);
  }

  /**
   * Adds a point, specified by the double precision arguments
   * <code>newx</code> and <code>newy</code>, to this
   * <code>Rectangle2D</code>.  The resulting <code>Rectangle2D</code>
   * is the smallest <code>Rectangle2D</code> that
   * contains both the original <code>Rectangle2D</code> and the
   * specified point.
   * <p>
   * After adding a point, a call to <code>contains</code> with the
   * added point as an argument does not necessarily return
   * <code>true</code>. The <code>contains</code> method does not
   * return <code>true</code> for points on the right or bottom
   * edges of a rectangle. Therefore, if the added point falls on
   * the left or bottom edge of the enlarged rectangle,
   * <code>contains</code> returns <code>false</code> for that point.
   *
   * @param newx the X coordinate of the new point
   * @param newy the Y coordinate of the new point
   * @since 1.2
   */
  public void add(double newx, double newy) {
    double x1 = Math.min(getMinX(), newx);
    double x2 = Math.max(getMaxX(), newx);
    double y1 = Math.min(getMinY(), newy);
    double y2 = Math.max(getMaxY(), newy);
    setRect(x1, y1, x2 - x1, y2 - y1);
  }

  /**
   * Adds the <code>Point2D</code> object <code>pt</code> to this
   * <code>Rectangle2D</code>.
   * The resulting <code>Rectangle2D</code> is the smallest
   * <code>Rectangle2D</code> that contains both the original
   * <code>Rectangle2D</code> and the specified <code>Point2D</code>.
   * <p>
   * After adding a point, a call to <code>contains</code> with the
   * added point as an argument does not necessarily return
   * <code>true</code>. The <code>contains</code>
   * method does not return <code>true</code> for points on the right
   * or bottom edges of a rectangle. Therefore, if the added point falls
   * on the left or bottom edge of the enlarged rectangle,
   * <code>contains</code> returns <code>false</code> for that point.
   *
   * @param pt the new <code>Point2D</code> to add to this <code>Rectangle2D</code>.
   * @since 1.2
   */
  public void add(Point2D pt) {
    add(pt.getX(), pt.getY());
  }

  /**
   * Adds a <code>Rectangle2D</code> object to this
   * <code>Rectangle2D</code>.  The resulting <code>Rectangle2D</code>
   * is the union of the two <code>Rectangle2D</code> objects.
   *
   * @param r the <code>Rectangle2D</code> to add to this <code>Rectangle2D</code>.
   * @since 1.2
   */
  public void add(Rectangle2D r) {
    double x1 = Math.min(getMinX(), r.getMinX());
    double x2 = Math.max(getMaxX(), r.getMaxX());
    double y1 = Math.min(getMinY(), r.getMinY());
    double y2 = Math.max(getMaxY(), r.getMaxY());
    setRect(x1, y1, x2 - x1, y2 - y1);
  }

  /**
   * Returns an iteration object that defines the boundary of this
   * <code>Rectangle2D</code>.
   * The iterator for this class is multi-threaded safe, which means
   * that this <code>Rectangle2D</code> class guarantees that
   * modifications to the geometry of this <code>Rectangle2D</code>
   * object do not affect any iterations of that geometry that
   * are already in process.
   *
   * @param at an optional <code>AffineTransform</code> to be applied to the coordinates as they are
   * returned in the iteration, or <code>null</code> if untransformed coordinates are desired
   * @return the <code>PathIterator</code> object that returns the geometry of the outline of this
   * <code>Rectangle2D</code>, one segment at a time.
   * @since 1.2
   */
  public PathIterator getPathIterator(AffineTransform at) {
    return new RectIterator(this, at);
  }

  /**
   * Returns an iteration object that defines the boundary of the
   * flattened <code>Rectangle2D</code>.  Since rectangles are already
   * flat, the <code>flatness</code> parameter is ignored.
   * The iterator for this class is multi-threaded safe, which means
   * that this <code>Rectangle2D</code> class guarantees that
   * modifications to the geometry of this <code>Rectangle2D</code>
   * object do not affect any iterations of that geometry that
   * are already in process.
   *
   * @param at an optional <code>AffineTransform</code> to be applied to the coordinates as they are
   * returned in the iteration, or <code>null</code> if untransformed coordinates are desired
   * @param flatness the maximum distance that the line segments used to approximate the curved
   * segments are allowed to deviate from any point on the original curve.  Since rectangles are
   * already flat, the <code>flatness</code> parameter is ignored.
   * @return the <code>PathIterator</code> object that returns the geometry of the outline of this
   * <code>Rectangle2D</code>, one segment at a time.
   * @since 1.2
   */
  public PathIterator getPathIterator(AffineTransform at, double flatness) {
    return new RectIterator(this, at);
  }

  /**
   * Returns the hashcode for this <code>Rectangle2D</code>.
   *
   * @return the hashcode for this <code>Rectangle2D</code>.
   * @since 1.2
   */
  public int hashCode() {
    long bits = java.lang.Double.doubleToLongBits(getX());
    bits += java.lang.Double.doubleToLongBits(getY()) * 37;
    bits += java.lang.Double.doubleToLongBits(getWidth()) * 43;
    bits += java.lang.Double.doubleToLongBits(getHeight()) * 47;
    return (((int) bits) ^ ((int) (bits >> 32)));
  }

  /**
   * Determines whether or not the specified <code>Object</code> is
   * equal to this <code>Rectangle2D</code>.  The specified
   * <code>Object</code> is equal to this <code>Rectangle2D</code>
   * if it is an instance of <code>Rectangle2D</code> and if its
   * location and size are the same as this <code>Rectangle2D</code>.
   *
   * @param obj an <code>Object</code> to be compared with this <code>Rectangle2D</code>.
   * @return <code>true</code> if <code>obj</code> is an instance of <code>Rectangle2D</code> and
   * has the same values; <code>false</code> otherwise.
   * @since 1.2
   */
  public boolean equals(Object obj) {
    if (obj == this) {
      return true;
    }
    if (obj instanceof Rectangle2D) {
      Rectangle2D r2d = (Rectangle2D) obj;
      return ((getX() == r2d.getX()) &&
          (getY() == r2d.getY()) &&
          (getWidth() == r2d.getWidth()) &&
          (getHeight() == r2d.getHeight()));
    }
    return false;
  }
}
